Funds P1, P3 have a negative correlation coe?cient -0.3 and funds P2, P5 a positive correlation cofficient +0.6. All other pairs of funds are uncorrelated. There are no restrictions on short selling and Pythagoras has a risk aversion parameter claculated to be t = 0.005 units.

1. Explain which investors short sell in this market and which funds they short sell. Are there any funds which no-one will short sell?